Improvement in mariners compasses



1. ma. VH. Buss.4 Compass.

N '1o3,237.` 4 l Patented May24,187o.

N. PETERS. PMOYD-UTHOGMPHER. WQSBNBTDN, D C.

tailed sie@ JOHN BLISS AND GEORGE H. BLISS. OF BROOKLYN, NEWV YORK.,

Letters Patent No. 103,287, lated May 2d, 1870.

IMPROVEMENT IN IVIIAIRIII'LEIIRSl COMPASSES.

Th Schedule referred to in 'chene Lettera Patent and making part of the same.

To all whom it may concern:

Be it known that we, J ons BLIss and GEORGE H. BLISS, ofrooklyn, in the county of Kings and State of New York, have invented an Improvement in Compasses; and we do'hereby declare the following to be a correct description of the same.

In the construction of the card, magnet, and oat of a liquid compass, 'we find by experiment that all uselessl weight must be dispensed with, in order that the magnetism may overcome the inertia of the parts, and cause them, with their cardinal points, to assume, in the shortest possible time, the proper position, af-

.ter having been moved from that position by the` nusteadiriess of the ship, -or other causes.

The magnetl or magnetsl heretofore used in compasses have been distinct and separate from the tioat or floating. material. `Welessen weight and increase the magnetic power by making the float itself, in whole or in part,of magnetized plates or sheetsteel, thereby dispensing with the materials which add weight, but possessino'directive magnetic force.

rlhe compass-cards and magnets heretofore cmployed have had transversebars, cases, o rprojeotions, which `form an impediment in the liquid to the movement of the cardby the magnet. \Ve therefore make the magnet'as a disk or plate of metal, and avoid projections or crossbars, and this magnet disk may be made of a single piece, or of several strips of stecl'soldered or attached together at the edges, so' as to run parallel to the north and south lines oi the compass-card. We ind that a i disk made up of strips has a superior directive force when magnet-ized, and is less influenced by extraneous forces.

The cardinal or other --divisions have heretofore been made'upon a disk or card, separate from the needle, and although 'such light-materials as thin mica have been made use of, still the same interfere with the card coming rapidly to the point of res't.

yWe increase the directive force by making the magnet as described, and at the same time dispense with -the weight of the card by making the divisions directly upon thc plate of metal forming the magnet.

Diiculty has been experienced in making the bowl of a liquid compass perfectly tight under the'varylng PTCSSUY@ @rising from expansion ci' the liquid by heat, especially where soldered joints are exposed tojthe liquid, and sometimes when cast-metal bowls are' used, the metal is porous and the bowl is heavy.

Ou account of the greater density of sheet-metal, `especially when spun up, we employ the same and construct the seatand ange for the glass and packing continuous with the bowl, in combination with the tube h and orifices 3 3,' and t', as the expansion or coutractiontakes place, as in an application for a patent heretofore made by us.

The case a is ot' sheet metal, (we prefer coppeiy) and this is shaped to form arest at 4 for the glass c, and a seat forthe packing d, as at 5, and the ring b is attached to the rim of the sheet metal, and the clamping-ring c presses the packing to place, and

makes the parts perfectly tight.

The ring l) is shown as attached to the portion 5, of the sheet metal; it might, however, extend below the flange 4, ,and he either attached or not, as de sired.

Themaguet formed of the sheet-steel disk or plate p, may be made of a perfect circle or oval, and

of one piece of metal, or of str ips of steel soldered together edgewise, as seen in fig. 2 netized as before mentioned.

The disk p is sustained-hy the bearing 15 upon the'pivot k, and the float o is made above t-he disk p, and attached at the edges. i

The disk p forms both the magnet, the compassat p', aud magcard, and part of the lioat. The divisions are to he made directly upon the disk p, by painting or engraving, .so as to avoid the weight of' a separate card.

The upper part o of the float may bc made in whole or iu part of sheet-steel, so as to be maguetized, and aid in the directive force of the compass; thus, there is very little material in the card or float, which is 'not magnetic, and, hence, but little iner-y tia of non-magnetic material to overcome therefore,

the compass will come to the place of rest more rap! idly than heretofore usual.

rlhe sheet metal o of the float is shown as made in a convexform; the disk p may also be either dat, concave, or convex, and may have annular ribs pressed up in the sheet metal if desired, for stiffcning the compass-card.

The divisions of he compass-card, when printed or painted upon a thin sheet of paper, and connected to the sheet metal of the needle, may be a couvenient'way of making the compass', 1n this case., the plate oi' mica, metal, or other substance heretofore required to stiiien the card, will be dispensed with, 4. The sentund iinnge, for the glass und packing the magnet itself performing both its -own duty and formed of the sheet metal of the bowl, in combination that of u foundation for the divisions. withl the rings for clamping the packing und glass to Wercluiin us our inventionthe fiziuge or seat, substantially as set fort-h. v

l.' rlhe magnet of ai compass made of u disk of' steel, Signed by us this 14th day of December, A. D. 1869. substantially as specified. I JOHN BLISS.

2. A compass, in which the divisions are made GEO. H. BLSS., upon the metal forming the magnet, substautiziily :is specified. y Witnesses:

3. The Hoot, mnde with nmgnetized sheet or plate GHAS. H. SMITH,

metal, substantially as specified. GEO. T. PINCKNEY. 

